Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2025 GMC Sierra 1500 owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2025 GMC Sierra 1500. The contact stated that while driving 75 MPH with the cruise control activated, the vehicle failed to accelerate as intended while depressing the accelerator pedal, and the vehicle decelerated to 10 MPH. In addition, the vehicle came to an abrupt stop independently. The contact's upper body almost struck the front windshield. There was no warning light illuminated. The contact stated that shortly afterwards, the vehicle resumed driving normally at 75 MPH; however, the failure reoccurred after a short distance. The vehicle failed to accelerate as intended while depressing the accelerator pedal and abruptly came to a stop. The vehicle then resumed driving normally. No warning lights were illuminated. The contact arrived at the residence, and the vehicle was towed to the dealer. The vehicle remained at the dealer awaiting a diagnostic test. …
The contact owns a 2025 GMC Sierra 1500. The contact stated that while driving approximately 5 - 10 MPH, the vehicle went into LIMP Mode and failed to properly accelerate, and the transmission unexpectedly downshifted. There was an electrical malfunction, which caused the transmission to downshift. An unknown message was displayed on the instrument panel. The contact stated that the network was not operating at the correct voltage due to the wiring harness. The engine light illuminated after the failure. The vehicle was towed on two occasions to the dealer to attempt to duplicate the failure. The dealer was unable to determine how to repair the vehicle. The vehicle was driven to the dealer in LIMP Mode. The manufacturer, General Motors, was contacted by the dealer, and the contact also reported the failure to the manufacturer. A General Motors service engineer had inspected the vehicle. …
The contact owns a 2025 GMC Sierra 1500. The contact stated while driving approximately 4 MPH and turning left into a parking spot, the vehicle independently accelerated. The contact stated that the brake pedal was depressed. The contact stated there was no warning light illuminated. The contact stated that the failure was intermittent, but the failure occurred while slowing down under 5 MPH and turning to the left. The contact had taken the vehicle to a local dealer; however, the failure was not duplicated. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was approximately 17,000.
I was driving at 70 mph on the highway. I heard clunk and then rattling and saw smoke while losing power. Check 4wd warning illuminated. Came to stop in busy traffic and where I first parked on shoulder, saw shoulder of roadway smoking and on fire. I pulled forward 100 or so feet slowly while hearing more grinding rattling cranking. Came to stop. Fire dept arrived and extinguished roadside blaze. Called towtruck and had towed to [redacted] in [redacted]. 75k miles. No warning just catastrophic failure.
Truck was in "Park" idling for 20 minutes when it went from Park to "Reverse" on its own. A person sitting in a dump truck saw the backup lights on my truck come on and the truck started backing towards his truck. My truck hit his truck causing damage to my left rear bumper.
The vehicle has a vibration and stuttering feel during highway driving. Cruise between 70-75 has off and on again vibration is seat, steering wheel, and center console. The issue feels more pronounced between 60-65 and exhibits more of a hum, much like a washing machine drum that is out of balance. I have had the truck at 2 different dealerships and they have insisted it was a whee balance issue. I have also had the truck balanced at Costco. None of these issues have been alleviated with wheel balance. The dealership, where the truck was purchased, refused to test the truck at highway speeds and would only drive it for a short period at speeds up to 55mph. I have also reached out to GMC customer service, and they simply regurgitated what the dealer indicated about balance and testing at 55 mph or less in town. There seems to be a number of TSBs out on this issue. …
Rough idle started at 11,400 miles. Took to GMC dealer near me and had thrust bearing clearance measured. Measured .0054"(within spec). They released truck back to me. 19,400 mile oil change found large metal(non magnetic) slivers in the filter media. I cut filters to check for issues due to known issues with this engine(metal). I called gmc corporate, i was told to not drive the truck. I paid out of pocket for the tow 142 miles away. Dealer told me they checked thrust bearing and came in at .0055", no noises, and no check engine light. Idle is very rough on start up. GM corporate stated a service advisor will call. Never got a call. I have sent and displayed the evidence and offered to show oil filter contents to both dealer and corporaten both have not done anything about this safety issue. This is a SEVERE safety issue. …
While driving at highway speed, my 2025 GMC Sierra suddenly began slowing down without warning and lost propulsion. When I pressed the accelerator, there was no acceleration response. The vehicle felt like it was braking or dragging instead of accelerating, creating a serious crash risk in traffic. A warning message appeared instructing me to "Put in neutral and restart truck." I followed the instruction, but the vehicle would not restart. It sounded like it was attempting to start, but it would not start normally. A "Service ESC" warning also appeared. The vehicle was towed by AAA to a GMC dealership and remains available for inspection. …
I own a 2025 GMC Sierra 1500 Denali equipped with the 6.2L V8 L87 engine, VIN [redacted]. The vehicle had approximately 35,000 miles when the engine experienced a catastrophic engine failure. Prior to/during the failure, the vehicle experienced abnormal engine noise and a loss of power. Multiple warning/alarm lights appeared on the dashboard, including the Check Engine and Traction Control warning lights. The engine failure resulted in a loss of motive power and made the vehicle unsafe to operate. PHONE# [redacted] The sudden loss of engine power while driving created a serious safety hazard because the vehicle could no longer operate normally in traffic and could potentially cause a crash. I am requesting that NHTSA document and investigate this engine failure as a potential safety defect involving the GM 6.2L L87 engine. …
In normal operation on Tuesday May 26,2026, the engine experienced catastrophic failure. The engine is the GM L87 6.2 Liter. This was on a highway in the country and I was able to maneuver the truck off the road before an accident occurred. It did leave me stranded and I was required to get it towed on a roll off (It was not drivable) to the dealer where I purchased it. The dealer [redacted] ) inspected my truck and has informed me that the issues with my 2025 Sierra match the issues for the recall GM had for the model years 2021-2025. It will require a new engine, radiator, among many other parts. There weren't any previous warnings. A check engine light only came on once the engine was engine came apart. An oil change on the vehicle by GM was done a month ago. The truck is a 2025 and has approximately 6,600 miles is all.
Transmission complaints in other Sierra 1500 years
Frequently asked questions
How common are transmission problems on the 2025 GMC Sierra 1500?
NHTSA has 27 complaints about the transmission & drivetrain of the 2025 GMC Sierra 1500, 22% of the model year's 122 complaints.
Is there a recall for 2025 GMC Sierra 1500 transmission problems?
No. NHTSA lists no transmission & drivetrain recall for the 2025 GMC Sierra 1500, though it has 1 recall for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2025 GMC Sierra 1500 transmission problems start?
Half of the complaints with a recorded mileage happened before about 17,000 miles, and 67% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 1 fire and 0 injuries to transmission & drivetrain problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.